RNA interference (RNAi) is the process in which small segments of double stranded RNA are used to identify and facilitate the destruction of target mRNA sequences. RNAi holds enormous potential both as a tool in molecular biology as well as a powerful therapeutic agent. Currently however there remain significant questions as to the viability of RNAi in medicine due to the difficulty in delivering the molecule effectively to areas of interest while maintaining its activity and avoiding toxicity. Whether advances in the systemic delivery of siRNA can effectively address these concerns is yet to be seen; technologies for the local administration of RNAi may offer more easily realized opportunities. Local delivery can limit numerous unwanted systemic side effects of therapies and maintains the highest load possible in the targeted area before clearance. Thus, there is a need to develop material systems for localized and sustained delivery of siRNA to tissues.